Apparatus for measuring steam-gas ratio



Aug. 8, 1944. I BROWN 2,355,052

APPARATUS FOR MEASURING STEAM-GAS RATIO Filed Oct. 26, 1942 4 Sheets-Sheet l 30 n. GALVANOMETER CURRENT SOURCE FIG. 2

far! If. Brown INVENTOR BYQJZ KM A TTORNEV Aug. 8, 1944. BROWN 2,355,052

APPARATUS FOR MEASURING STEAM-GAS RATIO Filed Oct. 26, 1942 4 Sheets-Sheet 2 IO 4O 5O BO v I00 RECORDER CHART DIVISIONS Earl H. BPOW/J INVE N 7' OR BYMK'M A Tram/E Aug. 8, 1944.

E. H. BROWN 2,355,052

APPARATUS FOR MEASURING STEAM-GAS RATIO Filed Oct. 26; 1942 4 Sheets-Sheet 3 GAS RATE. LITERS PER HOUR RECORDER CHART READING Earl H. Brown mms/vrm A T TORNEV Patented Aug. 8, 1944 Earl H. Brown, near Sheflield, Ala., assignor to Tennessee Valley Authority, a corporation of the United States of America Application October' 26, 1942, Serial No. 463,423

2 Claims. '(Cl. *13-51) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) The invention herein described may be manufactured and used by or for the Government for governmental punposes without the payment to me of any royalty thereon.

L This invention relates to the art of determining a variable composition, particularly when such composition consists of a mixture of readily condensable gasand relatively noncondensable The principle object of this invention is to provide an apparatus for the continuous determination of the amount of readily condensable gas or the ratio of readily condensable gas in a gaseous mixture containing relatively noncondensable gas. Other objects of this invention include the provision for an apparatus whereby the proportion of readily condensable gas in a gaseous mixture may be determined'continuously with a relatively high degree, of accuracy.

In carrying out certain manufacturing operations which involve the use of gaseous mixtures containing readily condensable gas and relatively noncondensable gas, it is necessary to maintainthe amount or proportion of constituents at a predetermined value in order that the most eflicient results may be obtained. The catalytic reaction between carbon monoxide and steam brated tube in an air bath until a constant temperature is attained, simultaneously closing the top of the tube to stop the gas flow, and inserting the gas-filled tube into a container of cold water, whereby the steam content of the tube is condensed, measuring the gas volume and calculating the steam-gas ratio. The first method is sufliciently accurate for plant control use but requires the constant attention of an operator. The second method is undoubtedly inaccurate, and the results obtained by its use are not reproducible since they may vary from 25 to 135 per cent of the results obtained by the first method.

' rected to a continuous method for measuring the amount of readily condensable gas by measuring the time required to separate a predeter mined quantity of condensate consisting of substantially all of the readily condensable gas from a stream of said mixture, and by determining the amount of readily condensable gas in said gaseous mixture from the relationship of the time required to separate said predetermined quantity of condensate and the amount of the gaseous mixture from which it was separated.

The apparatus of the present invention is directed to a combination of means for measuring the rate of flow of a stream of said gaseous mixture, means for condensing and separating said readily condensable gas therefrom, and means for indicating the time required for the collection of a predetermined quantity of condensate from said condensable material in relation to said rate of how of said gas.

In the accompanying drawings, which form a part of the specification and wherein reference symbols refer to like parts wherever they.

occur,

Fig. l is a schematic representation of one form of apparatus for the embodiment of the pre 3811i; invention wherein the amount of readily condensable gas in a gaseous mixture containing condensablegas and relatively noncondensable gas or the ratio of readily condensable to noncondensable gas in such a mixture is determined. Such a gaseous mixture is represented by a mixture of steam and water gas, wherein the proportion of steam therein requires accurate determination and control for uniform and etficient operation of carbon monoxide converters through which it is passed;

Fig. 2 is a wiring diagram of the Wheatstone conductance ratio bridge shown in Fig. 1 and illustrates the principles involved in the measurement of the amount of relatively noncondensable gas remaining after the separation-of condensable gas from the gaseous mixture in which they were originally associated;

Fig. 3 is a chart showing the relationship -between, the rate of flow of relatively noncondensable gas as shown by transverse chart scale divisions and time, as represented by the longitudinal movement of the recorder chart during the successive separation and-collection of a predetermined amount of condensable gas;

Fig. 4 i: a chart showing the relationship between rate of flow of relatively noncondensable gas and the'reccrder chart division readings; The method of the present invention is di- Fig. 5 is a nrmograph used for determining steam-gas ratio from the rate of flow 'of noncondensable gas and movement of the recorder chart as illustrated in Figs. 3 and 4.

In Fig. 1;. astream of a gaseous mixture con taining readily'conde nsable gas .and relatively noncondensable gasggsuen as a mixture of steam and water gas, is admitted to inlet i of condenser 3. The mixture of condensed water and water 'gas passes from outlet thereof into separator I from which the condensed water passes to collector 9, from which it passes through trapped siphoning outlet tube ii into a'calibrated automatically siphoning measuring chamber I3. Collector 9 and measuring chamber l3 are so placed that the level of the liquid in the measuring chamber i3 rises above the bottom of siphoning outlet ll before the siphoning fromcollector 9 is complete and the siphoning from measuring chamber l3 begins. This arrangement prevents gas from being trapped in siphoning outlet tube ii and prevents variation in the volume of condensate siphoned off each time. The water gas from separator 1 passes to U-' tube type flowmeter i5 with orifice i1 and' containing a relatively low conductive liquid i9 wherein pairs of electrodes 2i and 23 are partially submerged at all times. As shown in Fig. 1 and further amplified in Fig. 2, electrodes 2i and electrodes 23 and resistance 25 are located in the legs ofa Wheatstone conductance ratio bridge and variable resistance 21 provided for balancing the bridge in operation as indicated by galvanometer 29 when alternating current is applied from source 3 1. Resistance 25 and 21 and galvanometer 29 represent the combination. of elements used for either indicating or recording the effect of variable rates of flow of the relatively noncondensable gas through fiowmeter i5. Siphoning outlet tube ll of collector 9 contains sealed-in contacts 33 which are connected to one side of the Wheatstone bridge through a vacuum tube relay 35. The change in level of liquid i9 which serves as the manometer fluid for fiowmeter i 5 causes the ratio of conductance betw en electrode 2| and 23 to change. This conductance ratio is used as a measure of the flow of relatively noncondensable gas and is ordinarily indicated on a recorder chart. Each time a portion of condensate is siphoned from collector 9 into measuring chamber i3, electrical connection is made between contacts 33 whereby relay 35 is actuated and, in turn, shortcircuits one side of the Wheatstonebridge circuit with the resulting current break causing galvanometer 29 to become unbalanced, and the siphoning of the predetermined amount of condensate is then indicated by a horizontal line on th recorder chart.

In Fig. 3, curve 37, in general, represents the I rate of flow of relatively noncondensable gas after the separation of condensable gas from the gaseous mixtures containing the same. Portions of the curve 31, represented by 39 and 4|, indicate the shortcircuiting of the Wheatstone bridge with the resultin break in record of rate of flow of gas giving a record of time required for the separation of a predetermined amount of readily condensable gas. For the present purpose, it is more convenient to use the lineal movement of the chart for this purpose. During the time required for the 'collection of a predetermined quantity of condensate as indicated by portions of curve 39 and 4!, the lineal movement of the chart is 1.6 inches, and the average rate of-fiow of relatively noncondensable gas as represented by pornumerator:

The values so obtained are uncorrected for temperature, pressure. and water content of the relatively noncondensable gas. These correc tions are now applied to the rate of gas flow as read from a chart such as that shown in Fig. 4 and by application or the rates of gas flow so corrected and the movement of the chart in inches during the collection of apredeter minedamount of condensate, the ratio of condensable gas, such as steam. to noncondensable gas is read directly from a nomograph such as that shown in Fig. 5.

The application of the nomograph is illustrated by a chart movement of 1.6 inches (which is equivalent to a definite time for constant chart movement) required for the collection 0! 51 ml. or water condensed from a steam-gas mixture and the observed rate of flow of 119 liters/hr. (104 l./hr. S. T. P.) .or noncondensable gas during the period of collection or said water, with the resulting indication of a steam-gas ratio of 3.14.

The derivation of the formula for calculation of the ratio of readily condensable gas to relatively noncpndensable gas, as applied to a steam water gas mixture, is shown as follows:

Molecular weight 0! condensate is equivalent to 22.4 liters s. 'r. P.) 0! condensable gas (1) Volume of steam (liters S. 'l. P.) condensed between siphoning periods=mi. condensateX- (2) Volume of gas =l.'/hr (from chart calibration) time between siphoning periods. However, the time is measured as the distance the recorder chart moves, hence,

chart distance (in in.) between siphoning periods (ml. condensate) X22.4X( chart speed in in./hr.)

(gas i./ .)X(chart dist. in in.) l8X(press., temp. dz w.v. cart.) For any particular installation the chart speed and volume of condensate will be fixed and can be incorporated into a constant.

(ml. condensate 22.4X(chart speed in in./hr.) 8 18 v Temperature and pressure corrections, which vary with atmospheric conditions, should be converted to reciprocals to place this value in the Factor I 1 temp., press., and water vapor corr. (9)

By substituting factors I and H in Equation 7,

Factor IXFactor n l (iii era gas /h'r X(chart dist. HES 0) Factor II- Stea'rn-ges ratio cognizance is taken of the actual Factor I- 523 1 Factor n-m-Llfi and by the application of the values so obtained under Equation 10,

Steam-gas ratio- The method of the present invention is applicable to the determination of the amount of readily condensable gas or the ratio of readily condensable gas to relatively noncondensable gas in a gaseous mixture, wherein it is necessary to know the molecular weight of the readily condensable gas in order that a predetermined amount of condensate may be collected whether such amount corresponds to such molecular weight or any multiple thereof. Obviously, it is desirable to separate portions of condensate of uniform volume in order that factor I in Equation 8 may be a constant and thus materially simplify calculations. However, any variation in the volume of condensate collected does not in any way aflect the present method so long as volume collected. 1

It will be seen, therefore, that this invention actually may be carried out by the use of various modifications and changes without departing from its spirit or scope.

I claim:

1. An apparatus for continuously determining the ratio of readily condensable to relatively noncondensable gas in a gaseous mixture, which comprises ,the combination of (a) Means for condensing said readily condensable gas and separating said noncondensable gas from a stream of said gaseous mixture,

(1:) Means for collecting successive quantities of all of the cendensate produced wherein each quantity is equivalent to a predetermined volume of condensable material, I (0) Means for measuring the rate of flow of noncondensable gas so separated during the time required to separate each said quantity of condensate,

(d) Electrical means for recording the rate of flow so measured, and

(e) An electrical circuit means responsive to the flow of each successive quantity of condensate so collected and so associated with said electrical recording means to momentarily disrupt the record of rate of flow and thereby record the time required for the collection of each successive quantity of condensate. 2. An apparatus for continuously determining the ratio of readily condensable to relatively noncondensable gas in a gaseous mixture, which comprises the combination of (a) Means for condensing said readily condensable gas and separating said noncondensable gas from a stream of said gaseous mixture,

(1;) Means forcollecting successive quantities of all of the condensate produced wherein each quantity is equivalent to a predetermined volume of condensable material,

(c) Means for measuring the rate of flow of noncondensable gas so separated during the time requiredto separate said quantities of condensate,

(11) Means for recording the rate of flow so measured comprising an electrical circuit responsive to variations in said rate of flow, and

(e) A second electrical circuit means responsive to the flow of each successive quantity of con-' densate so collected comprising electrical contacts adapted to close said second circuit means during the time each successive quantity of condensate is collected and a relay respons'ive to that portion of the second circuit means containing the contacts, and so associated with the first mentioned electrical circuit that the operation of the relay momentarily'disrupts the record of rates of flow and thereby records the time required to collect the respective successive quantities of condensate.

' EARL H. BROWN. 

